1. Field of the Invention
The present invention relates to downhole tools typically used in the oil and related industries for providing an annular seal and/or anchor system between one conduit disposed in another, the most common example being referred to as a packer, which also includes an anchor system and provides an annular seal between the production tubing and the casing.
2. Background Art
There are many different downhole tools in the oil industry which require that a seal be established in the annulus between one conduit and another in the well such as between the well bore or the well casing, and well tubing or the like. These tools may relate to the drilling and completion of the well, the production of the well, servicing of the well, or abandonment of the well. Some such tools also require an anchoring system for holding the seal in position against either upwardly or downwardly acting pressure differentials, and in many tools, it is highly desirable or an absolute requirement to be able to release the seal system and/or the anchoring system and retrieve the tool with minimum effort.
One of the more common examples of downhole tools of this type is the packer used to provide an annular seal between the production tubing and the bore hole casing. Such packers are typically run and set in place either by on a tubing string, or a wire line setting tool. When set using a tubing string, the packer is typically set using hydraulic pressure in the tubing, hydrostatic pressure in the well bore or a combination of both, and also mechanically by the weight of the tubing. In most cases it is desirable to guard against premature setting by some tripping mechanism. Such packers can either be made as a combination of the tubing string, in which case the interior conduit of the packer is connected at top and bottom to the tubing, or can be a permanent type packer with an internal seal bore and latching system for receiving a seating nipple with latch so that the tubing can be retrieved while leaving the packer set in place. Either type of packer may be used to support tubing loads hanging from the bottom of the assembly or set in the top of the assembly. These types of packers may be associated with safety systems, expansion joints, multiple packer systems, or multiple tubing strings for multiple production zones.
In the past each type of tool tended to have markedly different construction and components to attain the features and performance necessary for specific applications. These tools tend to be complex, long, and expensive to manufacture, and the large number of different parts required for the multitude of different tools creates additional costs related to the large inventories of parts required.